Acoustics of baroque, classical and modern flutes

modern flute
B foot


Music Acoustics UNSW

modern B modern C classical C classical D classical flared baroque B3 B3
C4 C#4 D4 D#4 E4 F4 F#4 G4 G#4 A4 A#4 B4
C5 C#5 D5 D#5 E5 F5 F#5 G5 G#5 A5 A#5 B5
C6 C#6 D6 D#6 E6 F6 F#6 G6 G#6 A6 A#6 B6
C7 C#7 D7 D#7 E7 F7 F#7 multiphonics


a key depressed
a key not depressed
a part of the mechanism that is not normally touched
Details in fingering legend.

Acoustic schematic
a closed tone hole
an open tone hole

Non-specialist introduction to acoustic impedance
Non-specialist introduction to flute acoustics

Impedance spectrum of a modern flute with a B foot measured at the embouchure hole using fingering for G#4 and G#5. Z is plotted in dB, i.e. 20 log(Z/Pa.s.m-3).

The flutist uses the same fingering for G#4 and G#5, but changes the speed, length and shape of the jet. The first four minima can be played. These first five mimima support harmonics in G#4. In G#5, only the second and fourth minima are important. (Inaudible traces of the lower note are visible in the spectrum for G#5 which has tiny bumps at harmonics of G#4.) The acoustic diagram shows that there are two equivalent tone holes which, in principle, could each make the G-G# transition. Boehm's original key system ("open G#") did not have this inelegance, but he introduced this variation ("closed G#") because flutists were used to opening a hole with their LH fourth fingers. The two holes are rarely open at the same time.


Sound spectrum of a modern flute with a B foot played using fingering for G#5.

Sound Clip

You can hear G#5 played by Geoffrey Collins.

The Virtual Boehm Flute may suggest other fingerings for this note.
Fingering legend
How were these results obtained?
Acoustic measurements are available for these flutes -
modern B, modern C, classical C, classical D, classical flared, baroque
Sound clips are available for modern B, classical flared and baroque
To compare flutes, it is easiest to open a separate browser window for each instrument.

Copyright © Academic Press. JSV+ Joe Wolfe, John Smith, John Tann and Neville H. Fletcher, Acoustics of baroque, classical and modern flutes
Revised to include the baroque flute 2001.